Determination of 99Tc in fresh water using TRU resin by ICP-MS

- Tc(VII) can be extracted and purified from potential interferents with a TRU resin.
- Re(VII) can be used as a recovery tracer.
- No vaporisation step is needed for this method.
- Potassium permanganate can be used to elute Tc(VII) and Re(VII) from an anion exchange resin.
- A low detection limit of 4.01 × 10−13 Bq·L−1 was obtained.

Technetium-99 (99Tc) determination at trace level by inductively coupled plasma mass spectrometry (ICP-MS) is challenging because there is no readily available appropriate Tc isotopic tracer. A new method using Re as a recovery tracer to determine 99Tc in fresh water samples, which does not require any evaporation step, was developed. Tc(VII) and Re(VII) were pre-concentrated on a small anion exchange resin (AER) cartridge from one litre of water sample. They were then efficiently eluted from the AER using a potassium permanganate (KMnO4) solution. After the reduction of KMnO4 in 2 M sulfuric acid solution, the sample was passed through a small TRU resin cartridge. Tc(VII) and Re(VII) retained on the TRU resin were eluted using near boiling water, which can be directly used for the ICP-MS measurement. The results for method optimisation, validation and application were reported.

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